It is shown how the geometrical splitting of N-point Feynman diagrams can be
used to simplify the parametric integrals and reduce the number of variables in
the occurring functions. As an example, a calculation of the
dimensionally-regulated one-loop four-point function in general kinematics is
presented.Comment: 8 pages, 9 figures, contribution for proceedings of ACAT 2017
(Seattle, USA, August 21-25, 2017). arXiv admin note: substantial text
overlap with arXiv:1605.0482